Start singing the blues. Blue dresses are a cooler alternative to the classic LBD and make for a sizzling statement piece. There are a ton of hues to choose from; pick the tone that flatters you best. Katie opted for a casual look by pairing her berry blue tunic dress with leggings and flats; Marisa Tomei got glam in her silky frock; and Heather Graham paired her boho-chic dress with knee-high boots. All bodacious, all blue.